Additional source is being ignored while inheriting dependencies

• I am on the latest Poetry version.

• I have searched the issues of this repo and believe that this is not a duplicate.

• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: macOS Big Sur 11.6

• Poetry version: 1.1.11

Issue

Hi guys!
I'm using poetry for loading multiple projects and they depend on one another with the following structure:

.
├── project_1
│   └── pyproject.toml
└── project_2
    └── pyproject.toml

project_1/pyproject.toml

[[tool.poetry.source]]
name = "artifactory"
url = "https://pypi.example.com"
default = true

[tool.poetry.dependencies]
private_package = {version ="0.0.1", source = "artifactory"}

project_2/pyproject.toml

[tool.poetry.dependencies]
requests = "2.26.0"
fastapi = "0.65.3"

[tool.poetry.dependencies.project_1]
path = "../project_1"

And while I'm trying to execute poetry install or poetry update in project_2 it fails to find private_package (despite the same commands are working well inside project_1)
It makes me think that additional source, which was added in project_1 doesn't affect project_2

Can you please tell me if that's working well as designed and I'm trying to do something which is not supported entirely or if I'm misusing a tool and there's a lack of configurations?

Reproduce the reported setup using the two project_1 and project_2 pyproject.toml files, then run poetry install and poetry update in project_2 with -vvv. Check whether the source declared in project_1 is expected to apply to the inherited dependency. Done means establishing the supported behavior and either documenting it or identifying the relevant resolver change.